Power-actuating mechanism for typewriters



Oct. 23, 1928. 1,688,334

0. A. HOKANSON POWER ACTUATING MECHANISM FOR TYPEWRITERS Filed June 27. 1925 s Sheets-Sheet 1 Oct. 23, 1928. 4 1,688,334

' O. A. HOKANSON POWER ACTUATING MECHANISM FOR TYPEWRI'TERS Filed June 27. 1925 55 ShBBtS-Sheet 2 Oct. 23, 1928.

O. A. HOKANSON POWER ACTUATING MECHANISM FOR TYPEWRITERS Filed June 27, 1925 3 Sheets-Sheet 117" was.

, 7 In VEN TO/Y (W -2 xMw By wwxm Patented Oct. 23, 1928.

UNITED STATES PATENT OFFICE.

' OTTO A. HOKANSON, OF WOODSTOCK, ILLINOIS, ASSIGNOR TO WOODSTOCK TYI'EWRITEB C OIVIIRA ITSZ',- OF WOODSTOCK, ILLINOIS, A CORPORATION OF ILLINOIS.

POWER-ACTUATING MECHANISM FOR TYZPEWRITERS.

Application filed J'ime 27, 1925? Serial No. 39,935.

This invention relates to mechanism for actuating the type bars of a typewriting machine through the agency of a power actuated member, and has for its object the provision of mechanism of the class named which shall be easily controlled by the operator, which shall be rapid and uniform 'in its action, which shall be substantially noiseless and which shall consume a minimum of energy.

The invention is exemplified in the combination and arrangement of parts shown in the accompanying drawings and described in the following specification and it is more particularly pointed out in the appended claims.

In the drawings,

Fig. 1 is a fragmentary vertical sectional view through a typewriting machine, showing one embodiment of the present invention applied thereto.

Fig. 2 is a fragmentary side view showing an actuating solenoid.

Fig. 3 is a horizontal sectional view showing the arrangement of a portion of the actuating mechanism.

As illustrated in the drawings, the numeral 10 designates the frame of a typewriting machine having a cross bar 11 at the rear there. of, on which are pivotally mounted the key levers 12 provided with springs for holding them in their upper positions. The series of sub-levers 13 are pivoted at 14 on'the cross bar 15 and are arranged to actuate the type bars 16 through a pin and slot connection 17 in a well known manner. The sub-levers 13 are provided with actuators 18 which extend forwardly and are supported at the forward ends by springs 19. These springs normally press the actuators 18 rearwardly so as to return the type bars to their lowermost position after a printing operation and to retain them in this position. A pivot rod 20 eX tends across the frame of the machine and carries a pair of oscillating bars 21supported on arms 22 pivotally mounted on the rod 20. These bars operate as drivers for the type bars in a manner to be described. At each side of the typewriter frame 10 there is arranged a solenoid 23 having a connecting bar 24 provided with an inwardly proj ectlng pm 25 at its rear end. The pins 25 extend through slots 26 in the frame 10 and are pivotally connected at 27 to the arms 22 of the respective oscillating bars 21 When a soleno1d 23 is energized it will draw the plunger 24 1n- Wardly and rock the respective bar 21 forwardly and downwardly. Springs 28 are provided for returning the plungers when the solenoids are energized. Switch mechanlsm 1s provided for energizing one or the other of the solenoids when any one of the key levers 12 is depressed. Below the key levers 12 toward the front of the machine there is provided a pivot rod 29 extending across the frame from one side to the other. A pair of contact rods 30 is supported on the pivot rod 29 by arms 31 and 32. Each of the key levers 12 is provided with a shoulder 33 secured thereon in position to overlie the rod 30. Springs 34 normally hold the rods 30 against the lower faces of the stops 33. Interlocking mechanism 35 is provided for preventlng depression of more than a single key lever at one time. The arms 31 adjacent the slde walls of the frame 10 each carries a trigger 36 pivoted at 37 on an extension of the arm. The triggers 36 are provided with shoulders engaging lugs 38 projecting laterally from catch levers 39 which are pivoted at 40 on the side wall of the frame. A spring 41 holds the trigger 36 in engagement with, the lug 38, and a second spring 42 holds the lug '38 up against the shoulder on the trigger. The catch lever 39 is provided with a stop 43, which supports the end of a switch lever 44. The switch lever 44 is pivoted at 45 on the side of the frame 10 and is provided with a spring 46 tending to swing the lever in a counter-clockwise direction as viewed in F ig. 1. The switch lever is provided with a contact member 47 which bridges the space between two contact lugs 48 supported on the frame 10 but insulated therefrom. Conductors 49 and 50 are connected to the contact lugs 48 respectively so that movement of. the switch lever 48 closes the circuit of the solenoid 23 at the side of the machine adjacent theswitch lever operated. lVhen a key lever isdepressed the stop 33 will force the bar 30 downwardly, thus moving the trigger 36 downwardly and carrying the lug 38 in the same direction. This will release the stop 43 from the switch lever 44 and permit the spring 46 to close the switch, thus energizing the solenoid 23 and moving the plunger 24 to swing the bar 21 forwardly and downwardly. The downward movement of the trigger 36 will cause the forwardly projecting end thereof to strike a pin 51 and release the trigger from the lug 38. This will free the catch lever 39 so that it is urged in a counter-clockwise direction, as viewed in Fig. 1, by the spring 42. A link 52 connects the arm 22 with a pin 53 on the switch lever 44. A slot 54 is provided in the end of the link 52 to permit movement of the switch lever 44 when the bar 21 is in its uppermost position. The forward movement of the arm 22, however, will cause the end of the slot 54 to engage the pin 53 and return the switch lever 44 to its uppermost position. As soon as the switch lever reaches this position the stop 43 on the. catch lever 39 will spring into place beneath the end of the switch lever and thus retain the switch lever in. its open position. It will be seen that depression of the key lever will therefore energize the solenoid a sufficient length of time to cause a single movement of the bar 21 forwardly and downwardly. The forward movement will immediately break the solenoid circuit so that the bar will then be returned by its spring 28. Thus a single oscillation is imparted to the bar 21 at each depression of a key lever.

Each of the key levers 12 is provided with a contact member 55 pivoted at 56 thereon and having a pin and slot connection 57 to permit limited oscillation about its pivot 56. A spring 58 normally holds the contact member 55 in its forward position in registration with a lug 59 on the actuator 18. When a key lever is depressed the contact member 55 will force the actuator 18 downwardly to bring a tooth 60 thereon into the path of the bar 21. This movement will take place prior to' the release of the switch lever 44 so that when the solenoid 23 is energized the tooth 60 will be engaged by the bar 21 and the actuator 18 will be carried forwardly and downwardly with the bar. This will swing the sub-lever 13 upon its pivot 14 and produce a printing operation of the type bar 16. The actuator 18 is provided with a cam face 61 which engages an adjustable release screw 62, these screws being mounted on a bar 63 extending transversely of the machine frame. By adjusting the screws 62 the point at which the actuator is released from the bar 21 may i be regulated to control the force of the impression made by the type bar.

It will be observed that two oscillating bars 21 are providedand that separate solenoids and separate controlling means is provided for each of these bars. The bars are arranged at opposite sides of the typewriter and each bar is controlled by the keys at one side of the keyboard. The purpose of this arrangement is to permit a more rapid operation of the typewriter for a given speed of solenoid operation. The operator naturally strikes keys which are operated by different hands in closer timed relation than the keys which are operated by the fingers of the same hand. The arrangement described proyides separate actuating mechanism for the keys which will ordinarily be struck in the closet timed relation. The response of a solenoid may in some cases not be sufficiently quick to accommodate itself to the period between operation of keys by different hands of some operators, but where two solenoids are provided this difficulty will be avoided. The re sponse of a solenoid is ordinarily amply quick to produce a complete cycle of operation between the actuation of the keys by the fingers of a single hand. It will be apparent that in many cases a single solenoid will operate rapidly enough for the ordinary operator and forsuch cases one of the solenoids and its corresponding control mechanism may be omitted, and the oscillating bars 21 and con tact bars 30 continued entirely across the frame of the machine.

Other changes; within the spirit and scope of the invention as defined by the following claims, Wlll readily suggest themselves to those skilled in the art.

I claim:

1. In a typewriter having key levers and and mechanically operable thereby for tripping said trigger mechanismto permit said switch to close.

2. In a typewriter having key levers and type bars, the combination with an oscillating driver, a solenoid for operating said driver, a switch for closing the circuit of said solenoid, spring means for closing said switch, trigger mechanism for holding said switch open, means common to a plurality of key levers for releasing said trigger mechanism to close said switch when any one of said key levers is depressed, means for connecting a type bar with said driver when the key lever corresponding thereto is depressed, and means connected with said driver for openlng said switch after an operation of said driver.

3. In a typewriter having key levers and type bars, the combination with separate power devices arranged for separate operation and separately controlled by different sets of key levers at opposite sides of said typewriter for actuating their respective type bars and means for preventing simultaneous mechanism controlled by the keys at opposite sides of said typewriter for controlling said solenoids.

5. In a typewriter having key levers and type bars, the combination with a pair of power devices, means controlled by said key levers for connecting said type bars with said power devices, and means for preventing simultaneous operation of key levers at opposite sides of said typewriter, the key levers at one side ofsaid typewriter being arranged to connect type bars with one of said power devices while the key levers at the opposite side of said typewriter are arranged to connect type bars with the other of said power devices.

6. In a typewriter having key levers and type bars, the combination with a pair of drivers at opposite sides of said typewriter, a pair of solenoids for operating said drivers respectively, means controlled by the type bars at one side of said typewriter for energizing one of said solenoids, means for con necting the type bars corresponding to sa d key levers with the driver at said side of said typewriter when said key levers are depressed, means controlled by the key levers at the opposite side of said typewriter for energizing the circuit of the other solenoid when said last named key levers are depressed, means for connecting the type bars corresponding to said last named key levers with the driver operated by said last named solenoid when said last named key levers are depressed and means for preventing simultaneous operation of key levers at opposite sides of the typewriter.

7. In a typewriter having key levers and type bars, the combination with a driver, a solenoid for operating saiddriver, a switch for closing the circuit of said solenoid, trigger mechanism normally holding said switch open, means common to a' plurality of key levers and mechanically operated by said keylevers for tripping said trigger mechanism to effect closing of said switch when any one of said key levers is depressed, and means connected with said driver for restoring said switch and trigger mechanism to normal position with said switch open after the operation of said driver. I

8. In a typewriter having key levers and type bars, the combination with an oscillating driver, a solenoid for operating said driver, a switch for closing the circuit of said solenoid, a spring tending to close said switch, trigger mechanism for holding said switch open against the action of said spring, means common to a plurality of key levers and mechanically operable thereby for releasing said trigger mechanism to permit said switch to close when any one of said key levers is depressed, means for connecting a type bar with said driver when the key lever corresponding thereto is depressed, and means connected with said driver for opening said switch after an operation of said driver.

9. The combination with a typewriter having key levers and type bars, of a driver for operating said type bars, a solenoid for actuating said driver, means operated by a .key lever when depressed for connecting the type bar corresponding thereto with said drivei', a switch normally biased to circuit closing position for closing the circuit of said solenoid, a latch arranged to automatically engage said switch and hold said switch in open position when said switch is opened, a trigger for releasing said latch from said switch, a universal bar operable by said key levers for moving said trigger to release said latch when any one of said key levers is depressed, and a connection between said driver and said switch to open said switch at the close of an operation of said driver.

10. The combination with a typewriter having key levers and type bars, of a driver comprising a bar extending transversely of said typewriter and pivoted to oscillate about an axis parallel therewith, a solenoid for oscillating said bar, actuators for connecting saiddriver bar with said type bars, means operated by said key levers for moving the respective actuators into operative relation with said driver bar, means for automatically disconnecting said actuators from said driver bar at the end of an oscillation of said driver bar, a switch for closing the circuit of said solenoid, trigger mechanism for closing said switch when any one of said key levers is de pressed, and means operatedby said driver for opening said switch at the end of an oscillation of said driver, said trigger mechanism being arranged automatically to lock said switch in open position.

In testimony whereof I have signed my name to this specification on this 23d day of June, A. D. 1925.

OTTO A. HOKANSON. 

